Extrapulmonary oat-cell carcinoma presenting as a primary left ventricular tumor: A case report

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Extrapulmonary oat-cell carcinoma presenting as a primary left ventricular tumor: A case report Rami Khouzam, MD,a Jose Fernandez, MD, FACC, FACP,a,b Santiago Ramirez, MD,a,b Jose Gonzalez, MD, FACC, FACP,a,b and Gulshan Sethi, MD, FACC,a,c Tucson, Arizona

An asymptomatic 57-year-old man had an abnormal resting electrocardiogram and a positive treadmill stress test. Cardiac catheterization with left ventriculography revealed a large left ventricular mass in the apex, but otherwise normal coronary arteries. Excisional biopsy of the mass was consistent with oat-cell carcinoma. Additional evaluation was negative for metastasis. The patient was treated with combined chemoradiotherapy and was doing well at 16 months follow-up. (Heart Lung® 2002;31:229 –32.)

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he first antemortem diagnosis of cancer in the heart was reported in 1913, but reports of this nature did not appear in the English literature until 1930. Metastatic neoplasms to the heart and pericardium, although rare, are more common than primary cardiac tumors, and account for 1.5% to 20.6% (average 6%) of autopsies on patients with malignant diseases.1 Primary cardiac tumors are extremely uncommon, with a reported incidence of 0.001% to 0.28% in autopsy series. Benign myxoma of the heart is the most common type of primary cardiac tumors, accounting for more than 50% of all the primary neoplasms of the heart.2-4 The antemortem diagnosis of cardiac neoplasms is uncommon. Echocardiography is an extremely valuable, noninvasive test to detect cardiac tumors,5-6 and the electrocardiograph (ECG) also has been of some help in the diagnosis of tumors of the heart. The following case report presents a clinical course of a patient with primary oat-cell carcinoma in the left ventricle who had successful resection.

From the aTucson Hospitals Medical Education Program (THMEP), Internal Medicine Residency and Tucson Medical Center, bSection of Cardiology, Department of Internal Medicine, St. Joseph’s Hospital, and cDepartment of Cardiothoracic Surgery, University Medical Center, University of Arizona. Reprint requests: Rami Khouzam, MD, 2345 N Craycroft Rd, Apt 206, Tucson, AZ 85712. Copyright 2002, Mosby, Inc. All rights reserved. 0147-9563/2002/$35.00 ⫹ 0 2/1/124008 doi:10.1067/mhl.2002.124008

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CASE REPORT The patient is a 57-year-old white man without a significant medical history or symptoms. During a routine visit to his primary care physician, he had new ECG changes in the form of T-wave inversion in leads I, II, III, aVF and V4-6; biphasic T wave in V3; and poor R-wave progression in precordial leads (Fig 1a). These findings were different compared with an ECG completed 6 months earlier (Fig 1b). His examination was within normal limits. He had an 18 pack per year smoking history; however, he stopped smoking 17 years ago. He completed a treadmill stress test, per Bruce protocol. It was positive and showed ST depression ⬎1 mm with downward sloping in leads V4-6; reaching stage II and achieving 75% of expected maximum heart rate. The chest radiograph and routine blood chemistry evaluations were normal. A coronary angiogram revealed normal coronary arteries; however a left ventriculogram indicated a large multi-lobulated mass arising from the left ventricular apex (Fig 2). It was confirmed by a 2-D echocardiograph (Fig 3). A cardiothoracic surgery consult was obtained. Under moderate hypothermic and cardioplegic arrest, a left ventriculotomy was perfomed. A firm, whitish lobulated mass measuring approximately 5 cm ⫻ 4 cm ⫻ 3 cm and attached to the distal septum and apex of the left ventricle was excised. The ventricle was repaired with interrupted pledgetted sutures. Microscopic examination of the removed mass revealed a myocardium containing a

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Fig 1 (A) ECG showing T-wave inversion in leads I, II, III, aVF, and V4-6; biphasic T wave in V3, and poor R-wave progression in precordial leads. (B) Normal baseline ECG 6 months before the diagnosis.

primitive carcinoma characterized by small cells with a high nuclear-to-cytoplasmic ratio, frequent mitoses, extensive individual cell apoptosis, stippled salt-and-pepper nuclei, and nuclear molding. This was interpreted as consistent with a diagnosis of an oat-cell (small-cell) carcinoma (Fig 4). An exhaustive work-up was performed to uncover a possible primary focus elsewhere and assess for metastatic disease. These evaluations included computed tomographic (CT) imaging of the chest and abdomen, which were positive only for a few pretracheal and

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right hilar lymph nodes. A positron emission tomographic scan of the entire body was negative. A head CT and bone scan were also negative for metastatic disease. The patient was referred to a medical oncologist and received combined chemoradiotherapy. After 16 months, the patient was asymptomatic and had no evidence of recurrent disease.

DISCUSSION This report describes a case of primary cardiac oat-cell carcinoma in a patient without symptoms

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Primary cardiac oat-cell carcinoma

Fig 2 Left ventriculogram in diastole showing a large apical mass.

who has an abnormal ECG. The primary tumors of the heart are relatively uncommon and, until the advent of modern diagnostic methods, were diagnosed only at autopsy. Since the contribution of echocardiography, these tumors are being diagnosed with increasing frequency and, in most instances, successfully resected to achieve a cure. In contrast with primary tumors, the metastatic tumors of the heart and pericardium are 16 to 40 times more common, and resection of these tumors is almost always palliative. Myxoma of the heart accounts for almost 40% to 50% of all benign cardiac tumors and 25% of all the tumors and cysts of the heart and pericardium. More than 75% of all cardiac

Fig 4 Pathologic examination of the mass under microscopy revealing myocardium containing a primitive carcinoma characterized by small cells with a high nuclearto-cytoplasmic ratio, frequent mitoses, extensive individual cell apoptosis, stippled salt-and-pepper nuclei, and nuclear molding (hematoxylin eosin, original ⫻ 100).

Fig 3 2-D echocardiograph in a 2-chamber apical view showing a lobulated mass hanging from the apex.

tumors are benign. Most of these are myxomas (more than 50%), fibroelastomas, or rhabdomyomas. Among the malignant lesions, angiosarcomas, rhabdomyosarcomas, mesotheliomas, and fibrosarcomas are the most common. A primary oat-cell carcinoma of the endocardium has not been previously described in the literature. Previous authors have noted the paucity or complete absence of symptoms of primary cardiac neoplasms often despite extensive involvement of the heart by a tumor.2,3 Occasionally, however, hemodynamic compromise may occur. Involvement of the pericardium may lead to effusion, tamponade, or constriction. Myocardial carcinoma may lead to arrhythmias, sudden death, or less often, heart failure. Endocardial involvement may precipitate obstruction, valvular insufficiency, or tumor emboli. Ar-

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rhythmias (atrial flutter and fibrillation) and a wide variety of ECG changes are common in patients with cardiac tumors. Low-voltage, nonspecific ST-segment and T-wave changes and sinus tachycardia are occasionally associated with heart neoplasms.1 Although they may certainly be caused by tumor involvement of the heart, they are more often a result of concomitant factors such as electrolyte imbalance, hypoxia, or anemia. There are no classical ECG changes that are pathognomonic for cardiac neoplasms. Diagnostic studies include echocardiography, CT scanning, and magnetic resonance imaging. Contrast angiography, although invasive, can show the tumor size, location, and degree of mobility. Occasionally, radiographic studies may show calcification in the tumor, especially cardiac myxomas.7 The surgical approach to resect cardiac tumors depends on the site and extent of the lesion. The use of cardiopulmonary bypass is almost always required. Total excision is desirable for all cardiac neoplasms; however, if total excision will compromise the coronary arteries, the conduction system, or valve, then partial excision may be necessary. Fragmentation and embolization of the tumor are constant threats; thus surgeons should avoid vigorous palpation and manipulation of the heart before cardioplegic arrest. The epithelial origin of an oat-cell carcinoma was first recognized in 1926 by Barnard.8 Before that time, it was termed oat-cell sarcoma of the mediastinum. The intramucosal site of origin of this carcinoma is often difficult to identify, but, like carcinoid tumors, small-cell carcinomas are thought to arise from basal neuroendocrine or Kulchitsky’s cells. These peptide hormone–secreting cells are uncommon in the adult but abundant in the fetal lung.9 Approximately 4% to 6% of patients with an oatcell carcinoma have no obvious pulmonary or mediastinal primary focus on imaging, bronchoscopy, or sputum cytology. Extrapulmonary oat-cell carcinoma can occur in a variety of organs, including minor salivary glands, pancreas, esophagus, larynx, pharynx, colon, rectum, and uterine cervix. Although the clinical behavior of these tumors can vary on the

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basis of their site of origin, extrapulmonary oat-cell lung carcinomas are invariably aggressive with a median survival less than 1 year and a tendency to develop early nodal and disseminated metastatic disease.10,11 Oat-cell carcinoma originating from the pericardium has been described,12 as has a metastatic apical tumor of the left ventricle, in a patient with a bronchogenic primary tumor.13 This report presents a case of a left ventricular apical oat-cell carcinoma, believed to represent a true primary cardiac tumor, thus far not described in the literature. We thank Sami I. Said, MD, Professor, Pulmonary and Critical Care Medicine, The State University of New York at Stony Brook, NY, and Robert M. Aaronson, MD, FACP, FCCP, Pulmonary and Critical Care, Clinical Assistant Professor, University of Arizona, Tucson, AZ, for their critique of this case report.

REFERENCES 1. Braunwald E. Cardiac manifestations of neoplastic disease Philadelphia: WB Saunders; 1997. 2. McAllister HA Jr, Hall RJ, Cooley DA. Tumors of the heart and pericardium. Curr Probl Cardiol 1999;24:57-116. 3. Roberts WC. Primary and secondary neoplasms of the heart. Am J Cardiol 1997;80:671-82. 4. Harvey WP. Clinical aspects of cardiac tumors. Am J Cardiol 1968;21:328. 5. Janine K, Sanford W, Joseph K, Walter V, Arthur H. M-mode and cross-sectional echocardiographic diagnosis of right ventricular cavity masses. J Clin Ultrasound 1981;9:5-10. 6. Ports TA, Cogan J, Schiller NB, Rapaport E. Echocardiography of left ventricular masses. Circulation 1978;58:528. 7. Azzoparchi JG, Bellow AR. Carcinoid syndrome and oat-cell carcinoma of the bronchus. Thorax 1965;20:393-7. 8. Barnard WG. The nature of the oat-cell carcinoma of the mediastinum. J Pathol 1926;29:241. 9. Devita VT, Hellman S. Cancer. Principles and practice of oncology. Small cell lung cancer. Philadelphia: Lippincott Williams & Wilkins; 1993. 10. McAllister HA Jr. Primary tumors of the heart and pericardium. Pathology Annual 1979;2:325-55. 11. McAllister HA Jr, Fenoglis JJ Jr. Tumors of the cardiovascular system. Fascicle 15, second series. Atlas of Tumor Pathology. Washington DC: Armed Forces Institute of Pathology; 1978. 12. Cruz JJ, Abad M, Fonseca E, et al. Oat-cell carcinoma of primary location in the pericardium. Tumor 1993;79:144-6. 13. Koiwaya Y, Kawachi Y, Orita Y, Nakamura M, Hirata T, Yamamoto K, et al. Echocardiographic detection of metastatic cardiac mural tumor. J Clin Ultrasound 1980;8:443-6.

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